Alex Cora likes the idea of stretching out his long relievers in the bullpen

It’s customary to carry one or two long relievers in the bullpen, pitchers who can go three or more innings if needed.

In Kutter Crawford, Corey Kluber, Nick Pivetta, and Josh Winckowski, the Red Sox have four.

Manager Alex Cora isn’t just comfortable with the configuration, he prefers it.

“We’ve been talking about this structure for a while,” he said. “Last year it just didn’t happen. This is what we envisioned. If you can get multiple-inning guys, it can help us to reset the other guys.”

In the 27-year-old Crawford and 24-year-old Winckowski, the Sox have two righthanders who were developed as starters and have the durability to pitch three innings.

“From our standpoint, it’s the stuff they present late in the game,” Cora said. “It’s plus stuff.”

Crawford has a 1.29 earned run average in seven relief appearances covering 21 innings. Winckowski has a 2.23 ERA in 18 games over 32⅓ innings.

“I’ll go as far as they want,” Crawford said. “I can pitch three innings, maybe a little more at this point. I like it. I don’t have to hold anything back.”

Crawford’s fastball hit 96 miles per hour against Arizona on Saturday over 2⅓ scoreless innings. Winckowski has averaged 95 with his fastball and pumped it up to 97.

Cora believes Crawford and Winckowski could handle one-inning high-leverage situations late in the game. But he prefers to keep them stretched out in the event they are needed as starters.

“If something happens health-wise with the five [starters], maybe they’ll be the guys to step up,” the manager said. “We have to make sure we protect our rotation now and we have to protect the future, too.

“Early on, we had an idea that Tanner [Houck] was going to be a starter. But I kept saying he’s going to throw as many innings as possible. That’s what you want.”

Crawford went 4⅓ innings on the road trip that ended Sunday, allowing one run. Winckowski gave the Sox six innings and also allowed one run.

“That’s kind of like a start,” Cora said.

Kluber and Pivetta are in the bullpen after being demoted from the rotation.

Kluber has yet to pitch in relief. Pivetta has appeared three times and allowed three runs on seven hits over 8⅓ innings and struck out nine without a walk.

That’s far better than how he pitched as a starter.

“With this structure, we can take care of the starters and at the same time take care of the relievers,” Cora said.

With a doubleheader Saturday against Tampa Bay, the Sox will need one of their long men to pick up some innings, either as a starter or following an opener.

Change of direction

Jarren Duran hit .361 with a 1.006 OPS in his first 28 games this season, giving the Sox a needed lift when Adam Duvall landed on the injured list with a broken left wrist.

But he is 3 for 31 in eight games since, with 15 strikeouts.

“[Opponents] are going to make adjustments,” Cora said. “Now it’s time for him to make adjustments. He’ll be fine.”

Sunday’s 4-2 loss to Arizona was a good example of how teams are approaching Duran. He saw 19 pitches, only four of them four-seam fastballs.

There were six changeups, four breaking balls, three cut fastballs, and two sinkers.

“Everything is on the edge or off the plate,” Duran said. “I’ve got to keep grinding. I can’t let it bother me. They’ve been pitching really well to me lately, but that’s the game. It’s cat-and-mouse.”

Duran has struggled the last few games, going 3 for 31.Barry Chin/Globe Staff

Duran has crushed curveballs this year, and he saw only four against Arizona over three days.

“It’s just making sure I get my pitch,” he said. “Just being patient and understand that striking out is part of the game. We break down pitchers so much, I know they’re breaking me down.”

Reds next

The team the Sox have faced the fewest times in the regular season — the Cincinnati Reds — will be at Fenway Park for a three-game series starting Tuesday. The Sox have played only 17 games against the Reds since interleague play began in 1997. They are 14-3, 6-1 at Fenway Park. Brayan Bello is scheduled to face righthander Ben Lively Tuesday. Lively joined the rotation May 19 and since has allowed four earned runs over 11⅔ innings … Masataka Yoshida’s .379 on-base percentage is second among qualified rookies to Oakland’s Ryan Noda (.400). Yoshida also is second in RBIs with 29. Josh Jung of Texas has 35 … The Sox are 18-22 in interleague games the last two seasons … Duvall is scheduled to start his minor league injury rehab assignment Tuesday. He broke his left wrist April 9. He is on the 60-day injured list and cannot return until June 9.

Peter Abraham can be reached at peter.abraham@globe.com. Follow him @PeteAbe.